2022 CHIJ Phy Prelims P1&2 Ans

CHIJ SECONDARY (TOA PAYOH) PRELIMINARY EXAMINATION 2022 SECONDARY 4(EXPRESS) PHYSICS 6091/01 Paper 1 1 D 11 B 21 B 31 B 2 A 12 B 22 D 32 D 3 B 13 C 23 A 33 C 4 C 14 B 24 A 34 C 5 B 15 D 25 A 35 D 6 B 16 D 26 C 36 C 7 C 17 C 27 D 37 A 8 B 18 D 28 B 38 C 9 B 19 A 29 C 39 A 10 C 20 A 30 B 40 D Paper 2 6091/02 Qn Answers Mark 1(a) The distance travelled per unit time is increasing. 1 1(b) average speed = total distance / total time = 80 cm / 2 s = 40 cm/s or 0.4 m/s 1 1 1(c) Air resistance is increasing. Weight is constant/ remain unchanged. 1 1 2(a) - Gradient on a distance-time graph represents speed - Gradient of P is greater than gradient of Q 1 1 2(b) 120 km 1 2(c) Speed = distance / time = 120 km / 1.5 hours = 80 km/h 1 1 2(d) 1 3(a) - Appropriate scale - Correct resultant force indicated with double arrow - Correct addition of forces drawn - Range: 135kN to 165 kN 1 1 1

3(b) - The resultant force of the two tugboats is equal and opposite to the friction between ship and water. - Resultant force on ship is 0 N. 1 1 4(a) Volume = 3.6x0.35x0.025 = 0.0315 m3 Density = mass / volume = 23 / 0.0315 = 730 kg/m3 1 1 4(b)(i) W = mg = 23 x 10 = 230 N 1 1 4(b)(ii) Moment = force x perpendicular distance = 230 x 1.3 = 299 Nm 1 1 4(c) - When painter moves further to the right, his weight will create a clockwise moment about the right-hand support. - This clockwise moment is greater than the anti-clockwise moment due to the weight of the plank about the same pivot. 1 1 5(a) - Chemical potential energy Kinetic energy + Gravitational potential energy - Chemical potential energy is decreasing, kinetic energy is constant, gravitational potential energy is increasing. OR Chemical potential energy Gravitational potential energy + thermal energy + sound 1 1 5(b) All the chemical potential energy input by the cyclist is converted to thermal energy when the cyclist stops. 1 5(c) GPE = mgh 5700 = 60 x 10 x h h = 9.5 m 1 1 6(a) less same less greater same 1 1 1 1 1 7(a) Three errors: 1. Ultra-sound should be ultraviolet instead 2. The positions of microwaves and infra-red waves should be interchange. 3. Visible light is missing. It should be between ultraviolet and infra-red waves. 1 1 1 7(b) X-rays is used to check for internal cracks in metal structures. 1 8(a) - Bring positively charged rod near but not touching sphere. - Connect the earth connection to the sphere. - Remove the earth connection. - Remove the positively charged rod. 1 1 1 8(b) - When positively charged rod is brought near the sphere, electrons on sphere will be attracted to the left side of sphere. - When earth connection is connected to sphere, electrons will be at